Direct Measurement of the and Decay Branching Ratios with the XENONnT Experiment
E Aprile, J Aalbers, K Abe, MA Rmeileh… - arXiv preprint arXiv …, 2026 - arxiv.org
E Aprile, J Aalbers, K Abe, MA Rmeileh, M Adrover, SA Maouloud, L Althueser, B Andrieu…
arXiv preprint arXiv:2606.17920, 2026•arxiv.orgWe present precision measurements of $^{212}\mathrm {Pb} $ and $^{214}\mathrm {Pb}
$$\beta $ decay branching ratios using $^{220}\mathrm {Rn} $ and $^{222}\mathrm {Rn} $
calibration data from the XENONnT detector, a dual-phase liquid xenon time projection
chamber. Characterizing these isotopes is critical, as they lead to significant low-energy
backgrounds in rare-event searches. We report ground-state branching ratios of $(14.75\pm
0.20 (\mathrm {stat})^{+ 0.14} _ {-0.40}(\mathrm {sys}))\% $ for $^{212}\mathrm {Pb} $ and …
$$\beta $ decay branching ratios using $^{220}\mathrm {Rn} $ and $^{222}\mathrm {Rn} $
calibration data from the XENONnT detector, a dual-phase liquid xenon time projection
chamber. Characterizing these isotopes is critical, as they lead to significant low-energy
backgrounds in rare-event searches. We report ground-state branching ratios of $(14.75\pm
0.20 (\mathrm {stat})^{+ 0.14} _ {-0.40}(\mathrm {sys}))\% $ for $^{212}\mathrm {Pb} $ and …
We present precision measurements of and decay branching ratios using and calibration data from the XENONnT detector, a dual-phase liquid xenon time projection chamber. Characterizing these isotopes is critical, as they lead to significant low-energy backgrounds in rare-event searches. We report ground-state branching ratios of for and for , providing the most precise direct measurements of these transitions to date. These results contribute to enhancing background modeling for dark matter and neutrino experiments, improving sensitivity to solar neutrinos and physics beyond the Standard Model.
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